Failfast Mechanism for Failure Fencing

The failfast mechanism panics a failed node, but it does not prevent
the failed node from rebooting. After the panic, the node might reboot and
attempt to rejoin the cluster.

If a node loses connectivity to other nodes in the cluster, and it is
not part of a partition that can achieve quorum, it is forcibly removed from
the cluster by another node. Another node that is part of the partition that
can achieve quorum places reservations on the shared disks. The node that
does not have quorum then panics as a result of the failfast mechanism.